Sabina ketone

Wallach has prepared a-phellandrene synthetically from sabinenic acid by oxidising it to sabina ketone with potassium permanganate. This ketone was converted into its semicarbazone, and the latter compound treated with dilute sulphuric acid, when sabina ketone is not regenerated, but an isomer, which was found to be isopropyl-hexenone. By the interaction of this body with methyl-magnesium iodide, loss of water occurs with a simultaneous conversion into a-phellandrene, which appears to be a mixture of the dextro- and laevo- varieties. This syntheticallj prepared a-phellandrene has the following characters —... 

Sabina ketone, Cj Hj O, is not a natural constituent of essential oils, but is of considerable interest on account of its utility in the synthesis of other ketones. 

Hodgson et al. showed that a series of bis- and tris-homoallylic terminal epoxides underwent intramolecular cydopropanation to give a range of bicydic alcohols. A short asymmetric synthesis of sabina ketone based on this chemistry was demonstrated (Scheme 5.20). A practical advantage with this process is that the volatile epoxides can be replaced with readily available chlorohydrins, an extra... 

In the reaction of disubstituted alkynes, 1,3-migration of the acetate takes place to give allenyl esters that can be versatile substrates, especially for [3,3]-Cope rearrangements.333 1,5-Enynes have proved to be versatile substrates for the preparation of perfumery agents such as sabinol334 and sabina ketone.335 Transannular systems undergo similar reactions.336... 

Sabina ketone (XXIV)26 and the esters of chelidonic acid (XXV)6 are reported not to be reduced by aluminum isopropoxide in boiling isopropyl alcohol solution. Apparently no attempts have been made to... 

This reaction also gave the opportunity to open an access to various polycyclic derivatives, as illustrated by the transformation of the mixture of diaster eomers 133 into tricyclic derivative 134 as a single diastereomer, thanks to a completely stereoconvergent process. An interesting entry into carene 136 and carone derivatives 137 has also been disclosed by Fiirstner [88]. 1,5-Enynes have proven to be versatile precursors for the preparation of perfumery agents such as sabina ketone (Scheme 45). 

Reactions.—3-Isopropylcyclopent-2-en-l-one reacted with Me-SOl-NaH to give sabina ketone and sabinene oxide 619 the latter could be cleaved to p-menthan-1-ol.620 Thujone and isothujone (for nomenclature see ref. 59) coupled with methyl vinyl ketone under basic conditions to give an adduct that could be modified to sesquithujane (e.g. cubebane) derivatives.621 (—)-Isothujone with HCHO formed the 1-hydroxymethyl derivative that underwent Jones oxidation and decarboxylation to (+)-thujone.622 623... 

As I synthesized ( )-sabina ketone in 1976 by intramolecular carbene addition reaction, as shown in Figure 4.11, the similarity of A with sabina ketone led me to synthesize the proposed structure A of... 

Two essentially identical syntheses of sabina ketone (214), from two different laboratories have been described, following the route shown in Scheme 7 and... 

Sabina hydrate, T7 Sabina ketone, T7 Sabinene, T7 Sabinol, T7 Sakuranetin, Y6 Salsolidine, K2 Salutaridinol I, K4 Salvin, T33... 

There are several reasons why it may be advantageous to switch from an organoalkali into the generally less reaetive organomagnesium intermediate. Due to its electrophilicity, the magnesium reagent may exert push-pull control over the addition of allylmetals onto oxiranes. This is a key step, for example, in the synthesis of natural Sabina ketone 16 (Seheme 1-12). ... 

Scheme 1-12. K(Li) —> MgBr switch preceding oxirane/allyl coupling and cyclization to (-)-Sabina ketone (16).

Sabina hydrate, T7 Sabina ketone, T7 Sabinene, T7 Sabinol, T7 Sakuranetin, Y6 Salsolidine, K2 Salutaridinol I, K4 Salvin, T33 Samandarine, K9 Sandaracopimaric acid, T32 a-santalal, T28 Santalenes, T28 a-santalol, T28 Santanolide C, T22 Santolina alcohol, T17 Santonins, T21, T22 Sapogenins, T49 Sarin, Z3 ... 

Gaoni, Y. Base Induced Isomerizations of y,6-Epoxyketones - II. Syntheses in the Thujane Series. /),L-Sabina Ketone and D.L-Cis Sabinene Hydrate. Tetrahedron 28, 5525 (1972). 

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