Of -a-santalol

Further studies on the biosynthesis of ovalicin (57) have demonstrated the use of deuterium magnetic resonance in biosynthetic studies. Compounds (59)—(62), structurally related to (-)-a-santalene (58), have been isolated from the essential oil of Lavandula ojficinalis and L. hybrida " An alternative synthesis of a-santalol... 

In the course of developing stereospecific routes to trisubstituted double bonds, Corey et al. have completed an efficient synthesis of a-santalol (132), many stages of which involve recent synthetic techniques from Corey s laboratory. Thus (—)-7r-bromotricyclene (133) was converted into (134) by successive treatment with lithio-l-trimethylsilylpropyne, silver nitrate (desilylation), and potassium... 

Total synthesis of a-santalol.2 a-Santalol (7) has been synthesized from (—)-ir-bromotricyclene (1) by essentially the same procedure used previously by Corey and Kirst for the synthesis of trans,frans-farnesol (2, 240-241). The starting material was converted into the terminal acetylene (2) by reaction with lithio-1-trimethylsilylpropyne followed by desilylation (2, 239-240). This was converted into the propargylic alcohol (3) by way of the lithium derivative by reaction with paraformaldehyde. /run.v-Hydroaluruination was then effected by treatment with H-buty(lithium followed by diisobutylaluminum hydride. Treatment with iodine... 

Ozonolysis of a-santalol gives the acid (P9.1). Treatment of this with HC1 gives isomeric acid (P9.2) which can also be obtained from (3-santalol as... 

Tricyclanes and Quadricyclanes.—A new synthesis of a-santalol (466) has been described. Reaction of the (7r-allyl)nickel bromide complex (464) with the bromotri-cyclene (465) gave the benzyl ether (467) and its -isomer. Reductive cleavage with... 

By means of the strychnine salts, Paolini and Divizia have separated the t alcohols in a pure state. The mixture of the two alcohols as found in eandal-wood od is first carefully fractionated and the fractions separately treated with sodium and converted into the hydrogen phthalate, in the usual manner. The strychnine salts are then formed and recrystallised until the melting-point and rotatory power are constant. The pure isomerides are then obtained by saponification. The purity is confirmed by reconverting into the strychnine salts, which should yield on saponification a santalol of identical properties. The strychnine phthalate of a-santalol melts at 155, and has an optical rotation of... 

Electrophilic species, other than a proton, can be used, thus adding to the synthetic utility of this variation. One such example is the end-game solution to the total synthesis of a-santalol 61. ° The advanced intermediate 60 was treated with ylide 16. Formation of the P-oxido ylide with -BuLi and addition of formaldehyde provided a one-step procedure for alkene formation and elaboration to 61. 

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