Synthetic studies of withanolides. 5. Synthesis of jaborosalactone A, B, and D

M Hirayama, K Gamoh, N Ikekawa

Index: Hirayama; Gamoh; Ikekawa Journal of the American Chemical Society, 1982 , vol. 104, # 13 p. 3735 - 3737

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Citation Number: 27

Abstract

BICH, COBr, etherpy/P (OEt),/NaH, THF. 2 equiv of LICHA, THF,-78" C/1 equiv of (F'hS),, HMPA-THF,-78" C. application of our developed stereoselective epoxidation of steroidal 22- 0lefins,~ into 22 (R)-lactone 9. Osmium tetraoxide oxidation of 5 followed by tosylation afforded a 5: l mixture of tosylates 6a (syrup) and 6b (mp 83-85" C). The major isomer 6a, tentatively assigned as indicated,'was converted to the chiral22, 23-epoxide 7. ...