Natural product synthesis linalool

Very interestingly as far as organic synthesis is concerned, these biooxygenations can be conveniently performed on a scale of several grams (5 g), thus allowing easy preparation of either enantiopure diol. These can be conveniently used as chirons for the synthesis of various natural or non-natural products. For instance they can be cydized to the optically pure linalool oxides[168] or the corresponding tetrahydropyr-anols 169. ... 

Linalool and citral are important building blocks for the synthesis of isoprenoid natural products, e.g. vitamins A, E and K, carotenoids and a broad variety of fragrances. In view of changing starting materials in future decades due to limited amounts of fossil resomces, pinenes might be interesting somces for the fine chemical industry to produce linalool via pinane-2-hydroperoxide. The synthesis of linalool and citral from natural somces is discussed herein. 

Hotrienol was found for the first time in Ho leaf oil as the S enantiomer [7], but has been found since then in many natural sources for instance, the R enantiomer was found in black tea and in green tea. The product can be used in many flavours, such as eldertlower, grape, berry and honey flavours. It can be prepared from linalool obtained from citrus oils or Chinese Ho oils, but most linalool is obtained by synthesis from isoprene from petrochemical sources. 

Attention is drawn to the synthesis the oxygenated linalool oxide 896. This compound (and other stereoisomers) is not a naturally occurring monoterpenoid, but a fragment required in the synthesis of a calcium ion-selective ionophore, ionomycin, and was made from hydroxygeranyl acetate (113, R = Ac), then Sharpless conditions for introducing a chiral epoxide were used. The vital step is the cyclization of 897 by epoxidizing again under Sharpless conditions (titanium tetraisopropoxide and diethyl tartrate) when the product 896 is obtained. ... 

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