Synthesis of (R)- and (R)-4-methyl-6-2?-methylprop-1?-enyl-5,6-dihydro-2H-pyran (Nerol oxide) and Natural Occurrence of its Racemate
作者:G�nther Ohloff、Wolfgang Giersch、Karl H. Schulte-Elte、Paul Enggist、Edouard Demole
DOI:10.1002/hlca.19800630626
日期:1980.9.17
3-epoxy-citronellols (5) was prepared from (−)-(R)-linalool (3) via epoxy alcohol 4 and then reduced to (−)-(R)-3-hydroxy-citronellol (6). Sensitized photooxygenation of (−)-(R)-diol 6 led in part to (−)-(R)-triol 8 which was cyclodehydrated by dilute acid to a mixture of diastereoisomeric tetrahydropyran-4-ols 9 and 10. Dehydration of hydroxy ethers 9 and 10 afforded (−)-(S)-nerol oxide (11) and (+)-(R)-nerol
按照已知方法,由(-)-制备(-)-(2 S,3 R)-和(+)-(2 R,3 R)-2,3-环氧香茅酚(5)的混合物。(R)-芳樟醇(3)通过环氧醇4,然后还原为(-)-(R)-3-羟基-香茅醇(6)。(-)-(R)-二醇6的敏化光氧化部分导致(-)-(R)-三醇8,后者被稀酸环化脱水成非对映异构体四氢吡喃-4-醇9和10的混合物。羟基醚9和10的脱水分别得到(-)-(S)-氧化新戊二醇(11)和(+)-(R)-氧化新戊二醇(12),光学纯度为91%。从保加利亚玫瑰油中分离出的氧化氮(0.038%)被证明是外消旋的。这些结果为植物中氧化神经醇的形成提供了一些启示。