Journal of Organometallic Chemistry

Organotransition-metal-modified sugars: Part 17. Glucal-derived carbene complexes: synthesis and diastereoselective benzannulation

KH Dötz, F Otto, M Nieger

Index: Doetz, Karl Heinz; Otto, Frank; Nieger, Martin Journal of Organometallic Chemistry, 2001 , vol. 621, # 1-2 p. 77 - 88

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Citation Number: 19

Abstract

The addition of triisopropylsilyl and/or isopropylidene-protected 1-lithio-d-glucals prepared in situ from stannylated precursors 5 and 6 to hexacarbonyl chromium followed by methylation affords d-arabino-hex-1-enopyranosylcarbene complexes 7 and 8. They undergo a diastereoselective benzannulation upon reaction with tolan and 3-hexyne to give polyoxygenated chromans 9 to 12 in good yields and moderate diastereomeric excess ...