Cinnamates borohydrides

Sodium borohydride, even in a very large excess, reduced methyl 2-none-noate and methyl cinnamate incompletely to mixtures of saturated esters, unsaturated alcohols and saturated alcohols [1061]. On the other hand, a,p-unsaturated esters of pyridine and pyrimidine series were converted predominantly and even exclusively to saturated alcohols. Methyl 3-(7-pyri-dyl)acrylate gave, on refluxing for 1-2 hours in methanol with 10 mol of sodium hydride per mol of the ester, 67% of 3-(y-pyridyl)propanol and 6% of 3-(y-pyridyl)-2-propenol methyl 3-(6-pyrimidyl)acrylate gave 77% of pure 3-(6-pyrimidyl)propanol [1061]. 

This enzyme [EC 4.3.1.5] catalyzes the conversion of L-phenylalanine to tran -cinnamate and ammonia. The enzyme may also act on L-tyrosine. See also Dehydroalanine Borohydride Reduction... 

High yields of cinnamic alcohol can be obtained by reduction of cinnamaldehyde with alkali borohydrides. Formation of dihydrocinnamic alcohol is thus avoided [146]. 

Scheme 2 shows Rapoport s synthesis [15]. The cinnamic acid derivative 3 prepared from m-methoxy benzaldehyde [20] was ethylated by diethyl sulfate to give ethyl cinnamate derivative 4, followed by Michael addition with ethyl cyanoacetate to afford compound 5. Compound 5 was converted to lactam 6 by the reduction of the cyano group and subsequent cyclization. Selective reduction of the lactam moiety of 6 was achieved by treatment with trimethy-loxonium fluorob orate followed by sodium borohydride reduction. Amine 8 was obtained by the reductive methylation of amine 7. Amine 8 was converted to compound 9 by methylene lactam rearrangement [21], followed by selenium dioxide oxidation to provide compound 10. Allylic rearrangement of compound 10 and subsequent hydrolysis gave compound 12. The construction of the decahydroisoquinoline structure began with compound 12,... 

There is also present in this plant A - -hydroxy-jS-p-methoxyphen-ethylcinnamide (I) (mp 176°). This compound, for which the name aegeline is proposed, forms a dihydroderivative (mp 140°). Mild oxidation gave anisaldehyde and hydrolysis gave cinnamic acid. A synthesis was achieved by reacting p-methoxy-co-aminoacetophenone with cin-namoyl chloride in the presence of alkali and reducing the cinnamoyl derivative with sodium borohydride 4). 

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