Biomass as source of chiral synthetic tools

DAVID F. LLOMPART; MARÍA M. ZANARDI; VALERIA CORNE; AGUSTINA FRINCHABOY; ALEJANDRA G. SUÁREZ; ROLANDO A. SPANEVELLO

Golden

Otro; Summer School on Sustainability and Green Chemistry; 2009

American Chemical Society

Biomass is a widely available raw material which has been recognized as an important source of fuels and chemical products. By far, carbohydrates are the major annually renewable biofeedstocks from which to develop viable organic chemicals that are to replace those derived from fossil sources. Levoglucosenone (1) is a versatile and readily available member of the carbohydrate derived chiral pool, which has been intensively used as chiral synthon in the synthesis of a wide variety of compounds. This bicyclic enone is the major product of the pyrolysis of cellulose or cellulose-containing materials, such as waste paper.1 Our interest in this field is focused on the potential use of this chiral building block in the synthesis of new asymmetric inductors.2  Levoglucosenone 1 was obtained from microwave assisted or conventional pyrolisis of cellulose or waste paper.The chiral auxiliaries 2 and 3 were synthesized by the cycloaddition reaction of 1 with the appropriate 9-substituted anthracene, and the diastereoselective reduction of the carbonyl group afforded the corresponding chiral auxiliaries. The acrylate was simply prepared by the reaction of acryloyl chloride with the alcohols in the presence of triethylamine. The resulting acrylates were treated with cyclopentadiene in both thermal and Lewis acids conditions and the products were obtained with excellent diastereomeric excess.