Ralph Alexander Raphael CBE FRS FRSE (1 January 1921 – 27 April 1998) was a British organic chemist, well known for his use of acteylene derivatives in the synthesis of natural products with biological activity.

[8] Another was his collaboration with Franz Sondheimer on natural products including an insecticide extracted from Zanthoxylum clava-herculis (a diene then called herculin, now systematically named as (2E,8E)-N-isobutyl-2,8-dodecadienamide); work which led to Raphael's award of the Meldola Medal in 1948.

Despite having a slight stammer,[2] Professor Raphael was an inspiring lecturer who engaged his undergraduate students with up-to-date material on organic chemistry, based on his extensive knowledge of the current literature.

One on the synthesis of catenanes began with serious chemistry and gradually — imperceptibly — became less credible; it culminated in the description of their absorption spectra in the audible region" The output of Raphael's own work and that of his research group of postgraduate and postdoctoral students was published in over 150 peer-reviewed articles.

[18] Raphael studied many natural products, especially of the type that were biologically active and which would provide a challenge for synthesis but might be the realistic target of a single PhD student's thesis.

In 1951, co-worked and co-authored with J. W. Cook and A. I. Scott, he published the first synthesis of the quasi-aromatic compound tropolone and the thujaplicin natural products which contained this unusual ring system.

[6] Before the first synthesis by Ralph Raphael, thujaplicins had been naturally isolated from Chamaecyparis taiwanensis by Tetsuo Nozoe in 1936 (the β-isomer; hinokitiol),[21] and from Thuja plicata independently by Holger Erdtman in 1948 (all three isomers; α-, β- and γ-thujaplicins).

Ralph Raphael was keenly interested in the visual and performing arts, becoming a member of the Scientific Advisory Committee of the National Gallery in 1986; his favourite pastime was contract bridge.