COMMUNICATIONS TO THE EDITOR
May20, 1958
and alcohols has been reported to be catalyzed by boron trifluoride-etherate.2 We have found this reagent also to be effective in catalyzing the methylation of alcohols with d i a ~ o m e t h a n e . ~For example, the yield of P-cholestanol methyl ether was essentially unchanged by replacing the fluoroboric acid catalyst with an equimolar amount of boron trifluoride e therate. (2) Lf. S. Newman and P.F. B e a 1 , T ~ r sJOURNAL,^^, 5161 (1950). (3) Since this manuscript was written, similar observations were reported by E. Muller and W, Rundel, Angew. Chem., 7 0 , 105 (1958).
2383
groups developed an intense blue on standing for several months in sealed capsules. Volatile products incompletely characterized were obtained by the distillation of trimethylsilanol and aluminum isopropylate. The use of diethylsilanediol in place of trimethylsilanol with the appropriate isopropylate gave non-volatile polymeric substances which have not been characterized. Acknowledgment.-This work has been supported by the Office of Naval Research.
CONTRIBUTION No, 2332 DEPARTMENT OF CHEMISTRY GATESAXD CRELLIN COLLEGE JOSEPH D. DANFORTH OF CHEMISTRY MARJORIE C. CASERIO GRINNELL LABORATORIES GRINNELL, IOWA OF TECHNOLOGY CALIFORNIA INSTITUTE RECEIVED FEBRUARY 15, 1958 PASADENA, CALIFORNIA J O H N D. ROBERTS OF CHEMISTRY DEPARTMENT OF WISCONSIN hf. NEEMAN UNIVERSITY ~VILLIAMS. JOHNSON MADISON,~VISCONSIN TOTAL SYNTHESIS OF ALDOSTERONE RECEIVED APRIL14, 1958 Sir: CONDENSATION OF TRIMETHYLSILANOL TITANIUM ISOPROPYLATE
WITH
Sir: The preparation of glassy polymeric products containing Si-0-Ti bonds has been reported.' Because of interest in modified polymers, i t seems worthwhile to report a simple synthesis of several monomeric compounds containing silicon and titanium. The synthesis involves mixing trimethylsilanol and titanium isopropylate in the molar ratios desired in the product, usually in a solvent, and distilling to recover substantial yields of the product. A typical preparation for Ti [OSi(CH3)3]4 is given. To 0.1 mole (28.4 g.) freshly distilled titanium isopropylate in a 125-ml. distilling flask was added 70 ml. of 5.77 molar trimethylsilanol (0.4 mole) in dibutyl ether. The mixture became warm, was allowed to stand for about an hour, then distilled in vacuum to remove ether solvent and recover the reaction product. UYth no special precautions the recovery was 50-70y0 of theoretical. The products obtained in separate preparations using appropriate ratios of silanol to titanium isopropylate are summarized in Table I.
Carboti,/Calcd. % ' \Found Hydrogen, Calcd. Found % ?Z2'D
OC. B.P.iMm.
i
45.85 45.71 9.62 9.48 1.4490 114 13
I
II
m
TABLE I T i (OCaH;j,(OSi(CHd2
Formula
We disclose herewith a preparation of the adrenal hormone aldosterone (Ij by a highly stereoselective total synthesis which is basically different from previous approaches. The dihydroxy-ketone I I ( R 1 = H , R 2 = PH, R 3 = H2j2was converted into the li-furfurylidene derivative (R3 = CHC4H30)m.p. 193-194' which, on treatment with methacrylonitrilc in methanolic methoxide, was transformed into the adduct 11 (R1 = H , R 2 = -CH,CH(CHa)CN, R3 = CKCIH 3 0 ). 3 , 4 Acetylation, followed by ozonolysis, then
'Ti ( O C I H I ) ~ . (OSi(CHa)Jz
41.83 41.65 9.36 9.33 1,4408 120 11
Ti (OSi(CHY)~)~
35.65 35.81 8.98 9.05 1,4300 100 2
The condensation product containing two silanols and two isopropyl groups would be expected to exhibit two arrangements if the titanium is square and planar. No separation was attempted. Each of the titanium products was a water white liquid as prepared, but those containing isopropoxy ( 1 ) K . A. Andrianov. T. N.Janina and E . N. Kh,rustaleva, I z w s l , A k n i l . .Vai(k, S . S . S . R . , nliiei, Khinz X n z i k , 7!JR--X04 ( I R j i i ) ; Chrm. : l b ~ h . , 51, :it87 (1957).
(1) (a) J. Schmidlin, G. Anner, J . R. Billeter and A . !T'eit.triit, Experieiztia, 11, 365 (1953), el s e q . to J . S. Schmidlin, Q. Anner, J . ;: Billeter, K . Heusler, H. Uebermaiser, P. Wieland and A . Wett.;+rl.i Helv. Chim. A c t a , 40, 2291 (1957): (b) A . Lardon, 0. Schindler .:n I T. Reichstein, { b i d . , 40, W i f i (1937) ( 2 ) W. S. Johnson, R. Pappo and W. 1'. Johns, T H I SJ O V R X A I . , 78, 6339 (1956). (3) This product was a mixture of Cnn epimers t h a t could be employed in the succeeding steps without separation because t h e a s y n metry of Czo was ultimately eliminated. I n the preliminary study t!;e mixture was separated a t the diketone stage I I I a ( R ' = R2 = C O C H B , R y = Ac) and each epimer examined separately in the succeeding rewtions. ( 4 ) C / . W. S. Johnson, I). 0 . RIartin, R. Pill)pn. S. D . Darling and 11. A . Clement. Proceeriitrgy. .iR (l9;7),
