7424 propylmethylcarbinol, which was isolated as a white solid after removal of solvents. Recrystallization from pentane, sublimation at 0.3 mm and room temperature, and recrystallization from pentane to a constant mp of 73-73.5” gave pure material: nmr (CDCI,) 6 3.8 (m,1 H, CH3-CH-OH), 2.2 (s, 1 H, OH), 1.8-1.2 ppm (m, with two singlets and one doublet (J = 8 Hz) visible, 10 H); ir (CS2) 3615 s. 3480 m, broad, 3000 sh, 2980 and 2965 s (doublet), 2935 s, 2875 m, 1390 sh: 1380 m, 1360 sh, 1325 w, 1255 s, 1235 w, 1165 s, 1135 s, 1110 s, 1095 sh, 1050 s, 1030 m, 1000 w, 980 s, 940 m, 890 S , 855 m, 830 s, 810 sh, and 730 m cm-1; mass spectrum 45 (100) [HOCHCHa], 67 (10) [CjHi], 103 (11) ( M C1C2HIO].138 (8) [M - C?H,O], 182 (parent ion, not seen, as is usual for secondary and tertiary alcohols). Anal. Calcd for CjHI20CI2: C, 45.92; H. 6.61; CI, 38.73. Found: C, 45.61; H, 6.69; CIS38.34. A by-product (14% yield) in this reaction was 1-(1-methyl-2,2dichlorocyclopropy1)propene-1: nrnr (Cci,) 6 5.8 (m, 2 Ha), 2.1 (d, 3 H: J = 5 Hz, Hb), 1.75 Ppm (m, 5Hc). Anal. Calcd for
C7H,oC12: C, 50.94; H, 6.11; C1, 42.96. Found: C, 51.07; H, 6.60; C1, 42.64. This product is derived from CClz addition to 2-methyl-1,3-pentadiene. The latter most probably was formed by acid-catalyzed dehydration of the starting alcohol, the acid (HClj arising from that portion of CC12 attack on the alcohol which occurs at the 0-H bond.
Acknowledgments. The authors are grateful to the U. S . Air Force Office of Scientific Research (SRC)OAR for generous support of this research (USAF Grant AFOSR-68- 1350).
Addition of Grignard Reagents to Vinylsilanes Glen R. Buell,la’bRobert Corriu,lc Christian Guerin,lc and Leonard Spialterl“
Contribution f r o m the Chemistry Research Laboratory, Aerospace Research Laboratories, OfJice of Aerospace Research, Wright-Patterson A F B , Ohio 45433, and Laboratoire de Chimie Organique Physique, Faculte des Sciences, 86-Poitiers, France. Receiued March 26, 1970 Abstract: The addition of Grignard reagents to vinylsilanes has been investigated with respect to the nature of the Grignard and to the substituents attached to the silicon atom. Alkoxy and chloro groups were found to exert an activating effect to the extent that quantitative yields of addition products frequently are observed. The structure of the Grignard reagent was found to have a pronounced effect, the order of reactivity being tertiary > secondary > primary.
T
he addition of organolithium compounds to t h e double bond of vinylsilanes (eq 1) is well documented.2-5 In contrast, the only report of an analo-
CHFCHSi(Me),OEt
i-PrMgBr
-+ HzO
i-PrCHzCHSi(Me)20Ete
1
Hi0
R‘Li
MgCl
CH2=CHSiR3 +R’CH?CHSiR3+R’CH2CHzSiR3 (1)
,
i-PrCHzCHzSi(Me)20Et(4) 100%
Li
gous addition reaction with Grignard reagents is between phenylmagnesium bromide and triethylperfluorovinylsilane. *,$ Reinvestigation has shown that numerous Grignard reagents add to the vinyl group of vinylsilanes and that the extent of the reaction is sensitive t o t h e substituents a t t a c h e d to the silicon atom ( e q 2-4). i-PrhlyC1
When vinylsilanes containing labile groups on silicon (e.g., chloro, alkoxy) are allowed to react with a Grignard reagent, one can envision two possible modes of reaction: (a) addition to the a- or P-carbon of the vinyl group, or (b) displacement of the labile group from the silicon atom (eq 5). Examination of the reaction
Hz0
CHz=CHSi(Me)3-ei-PrCHzCHSi(Me)3--f I
R’MgX
CH2=CHSiR3-,Y, -+ R’CH2CHzSiR,-,Y,
+ CH3CHR’SiR8-,Y, + CH2=CHSiR3-.Y,-,R’
i-PrhIgBr
H20
CH2=CHSi(Ph)zH -+ i-PrCHaCHSi(Ph)ZH + I MgBr i-PrCHzCHzSi(Ph)zH (3) 10% (1) (a) Aerospace Research Laboratories; (b) to whom correspondence should be addressed; (c) Faculte des Sciences. (2) (a) L. F. Cason and H. G. Brooks, J . Amer. Chem. Soc., 74,4582 (1952); (b) L. F. Cason and H. G. Brooks, J . Org. Chem., 19, 1278 (1954).
(3) D. Seyferth, T. Wada, and G. Raab, Terrahedron Lett., NO. 2 2 , 20 (1960). (4) M. R. Stober, I
