starting with 350 mg 0 94 mmol of the above ethyl ester 170 mg 23 of n methyl 4 5 6 7 8 tetrahydro 5 5 8 8 tetramethyl 2 naphthyl 2 pyrroleacrylic acid are obtained with a melting point of 185 6 u00b0 c in a similar manner to example 3 b by reaction of 6 43 g 27 7 mmol of 5 6 7 8 tetrahydro 5 5 8 8 tetramethyl 2 naphthylboronic acid with 2 7 ml 23 1 mmol of 4 bromobenzaldehyde 2 05 g 24 of 3 5 6 7 8 tetrahydro 5 5 8 8 tetramethyl 2 naphthyl phenylcarboxaldehyde are obtained in the form of a pale yellow oil in a similar manner to example 1 d by reaction of 800 mg 2 7 mmol of 3 5 6 7 8 tetrahydro 5 5 8 8 tetramethyl 2 naphthyl phenylcarboxaldehyde with 650 ml 3 3 mmol of triethyl phosphonoacetate 900 mg 91 of the expected ethyl ester are obtained in the form of a colourless oil in a similar manner to example 1 e starting with 1 22 g 2 7 mmol of the above ethyl ester 380 mg 41 of 3 5 6 7 8 tetrahydro 5 5 8 8 tetramethyl 2 naphthyl phenylacrylic acid are obtained with a melting point of 210 1 u00b0 c in a similar manner to example 10 b by reaction of 4 g 23 mmol of 4 bromo 2 pyrrolecarboxaldehyde with 1 7 ml 27 6 mmol of iodomethane 2 3 g 50 of the expected product are obtained with a melting point of 123 4 u00b0 c.