Tetra hydrozerumbone 2, which has a powerful balmy fragrance, has a stereogenic carbon at C2 and can be easily prepared from zerumbone 1, which is one of the most important materials that displays ail NMRDOS character. Reduction of 2 gave two diastereomers 3 and 4: their optically active (>99% ee) alcohols were obtained by lipase-catalyzed stereoselective transesterification of each racemic alcohol. The enantioselectivity of tetrahydrozerumbol does not entirely depend on the hydroxyl position but on the 2-methyl position Compounds (R)-2 and (S)-2 were obtained by Dess- Martin oxidation of the corresponding alcohols. Interestingly, (R)-2 showed a strong balmy fragrance while (S)-2 had hardly any fragrance (c) 2009 Elsevier Ltd. All rights reserved.
Efficient synthesis of an optically active tetrahydrozerumbone exhibiting a fragrance and the application of zerumbone derivatives with a medium ring structure
作者:Takashi Kitayama、Ayumi Saito、Sayo Ohta
DOI:10.1016/j.tetasy.2012.09.016
日期:2012.11
(R)-Tetrahydrozerumbone 2, which has a powerful balmy fragrance, contains a stereogenic carbon at the C2 position and can be easily prepared from zerumbone 1, one of the most important materials displaying an NMRDOS character. The reduction of 2 gave two diastereomers of tetrahydrozerumbol 3, and the optically active (>99%ee) alcohols were obtained by a lipase-catalyzed stereoselective transesterification of each racemic alcohol. A barrier to this development is a long reaction time (about four weeks) and the need to separate the diastereoisomers. The desired (2R)-form of 3 was efficiently obtained by a lipase-catalyzed transesterification under optimized conditions using a diastereomeric mixture of racemic 3 as the starting material without separation of the diastereomers. Using this method, the reaction of other zerumbone derivatives is greatly improved. (C) 2012 Elsevier Ltd. All rights reserved.
Tetra hydrozerumbone 2, which has a powerful balmy fragrance, has a stereogenic carbon at C2 and can be easily prepared from zerumbone 1, which is one of the most important materials that displays ail NMRDOS character. Reduction of 2 gave two diastereomers 3 and 4: their optically active (>99% ee) alcohols were obtained by lipase-catalyzed stereoselective transesterification of each racemic alcohol. The enantioselectivity of tetrahydrozerumbol does not entirely depend on the hydroxyl position but on the 2-methyl position Compounds (R)-2 and (S)-2 were obtained by Dess- Martin oxidation of the corresponding alcohols. Interestingly, (R)-2 showed a strong balmy fragrance while (S)-2 had hardly any fragrance (c) 2009 Elsevier Ltd. All rights reserved.