Efficient C-21 deoxygenation of 21-alkoxy-20-keto corticoid steroids with trimethylsilyl iodide in the presence of methanol

…, Y Kunitama, M Numazawa

Index: Nagaoka, Masao; Kunitama, Yurie; Numazawa, Mitsuteru Journal of Organic Chemistry, 1991 , vol. 56, # 1 p. 334 - 338

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Citation Number: 10

Abstract

Reaction of 21-alkyl ethers 1, 4-6, 8, and 9 with a large excess of trimethylsilyl iodide (TMSI) produced the deoxygenated products 3 and 11 in low to moderate yields along with a small amount of 21-alcohols 2 and 10. The deoxygenation reaction in the presence of 1.5 molar equiv of MeOH gave the products in much higher yields than those without MeOH, except the reaction of the ethyl and n-propyl ethers 4 and 5. Treatment of 1 and 8 with ...