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Paper | Regular issue | Vol 36, No. 10, 1993, pp.2397-2405
Published online, 1st January, 1970
DOI: 10.3987/COM-93-6482
Synthesis of a Key Intermediate for D-Biotin via 1,3-Cycloaddition of a Thiocarbonyl Ylide and Sila-Pummerer Rearrangement

Toru Yamano, Mitsutaka Tanaka, and Kunio Takanohashi*

*Technology Development Laboratories, Takeda Chemical Industries, Ltd., Juso-honmachi, Yodogawa-ku, Osaka 532, Japan

Abstract

An efficient preparation of a d-biotin intermediate, (±)-(3aα,4α,6aα)-1,3-dibenzyl-3a,4,6,6a-tetrahydro-4-hydroxy-1H-thieno[3,4-d]imidazol-2(3H)-one was accomplished by use of 1,3-cycloaddition of a thiocarbonyl ylide, Curtius rearrangement and sila-Pummerer rearrangement. Addition of p-toluenesulfonic acid was found to be effective to promote sila-Pummerer rearrangement of sterically unfavorable anti-2-trimethylsilyl sufoxide.