260
Journal of'the American Chemical S o c i e t y
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101:l
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January 3, I979
reduction (LiAIH4, Et20, 0 "C): (4) oxidation (Cr03PyHCI, CH2C12,RT). by medium-pressure column chromatography (silica gel; Satisfactory spectroscopic data (mass spectrum, 'H NMR, IR, etc.) were hexane-methylene (48:48:4)); (3) L ~ A I H ~ (7) obtained for this substance. reduction Of the separated diasteromeric urethanes to the le(8) T. Matsumoto, Y. Hosoda, K. Mori, and K. Fukui observed a highly stereospecific hydroboration on a very similar system to 3 (Bull.Chem. Soc. Jpn., vorotatory (@D - I 1.07' (c 3.63, CHC13)) and dextrorotatory 45, 3156 (1972)). ( a 2 %-t1 1.13' (c 1.77,CHC13)) alcohols 5 , respectively. (9) R. W. Kilb, C. C. Lin, and E. B. Wilson, Jr., J. Chem. Phys., 26, 1695 ( 1957). Pyridinium chlorochromate oxidation13 of the levorotatory (10) D. R. Herschbach and L. c. Krisher, J. Chem. PhyS., 26,728 (1958). alcohol 5 in methylene &loride at temperature yielded (1 1) A. A. Bothner-By, C . Naar-Colin, and H. Guenther, J. Am. Chem. Soc., 84, 2748 (1962). the aldehyde 6' ( ' H N M R (CDC13) 6 1 , I 1 (3 H, d, J = 7 Hz), (12) For example, see E. L. Eliel, N. L. Allinger, S. J. Angyal, and G. A. Morrison, 1 ,32 (3 H, d, J = 7 Hz), 3.28 (3 H , s), 9.4 1 ( 1 H, d, J = 1.8 "Conformational Analysis", Interscience Publishers, New York, 1965, p Hz)) i n 88% vield. Condensation of 6 in T H F at -78 OC to 19 . _ f. f. . (13) E. J. Corey and J. W. Suggs, Tetrahedron Lett., 2647 (1975). -50 'C wiih the phosphonate anion prepared from (14) The amount of the corresponding trans ester, i f any, should be
